A method and apparatus for monitoring an elevator drive brake wherein the method includes the steps of detecting a spring force (Fs-closed) when the brake is closed, detecting a spring force (Fs-open) when the brake is open, determining the difference between the two detected spring forces (ΔFs), and comparing the difference between the two detected spring forces with at least one preset permissible force differential (ΔFsmin; ΔFsmax) to determine whether the brake is defective. The apparatus includes a force sensor for each brake spring to be monitored, and an electronic monitor that stores at least one preset permissible force differential (ΔFsmin; ΔFsmax) and, during operation, compares the at least one preset permissible force differential with an actual force difference (ΔFs) between an open spring force (Fs-open) and a closed spring force (Fs-closed) as detected by the force sensor.
BRAKE FORCE MONITORING OF AN ELEVATOR BRAKE
2017-01-05
Patent
Electronic Resource
English